The high surface area of lithium metal can be a deterrent for its use in a variety of applications because of its pyrophoric nature. It is known to stabilize lithium metal powder by passivating the metal powder surface with CO2 such as described in U.S. Pat. Nos. 5,567,474, 5,776,369, and 5,976,403, the disclosures of which are incorporated herein in their entireties by reference. The CO2-passivated lithium metal powder, however, can be used only in air with low moisture levels for a limited period of time before the lithium metal content decays because of the reaction of the lithium metal and air. Thus there remains a need for stable lithium metal with an improved storage life.